November/December 2004

IG Instructions

Roving Muntin Gangsby Mike Burk

The demand for windows containing muntins or grids continues to grow. At some manufacturing facilities the percentage of insulating glass units containing internal muntins exceeds 80 percent. Inefficient and outdated muntin fabrication and insertion methods can impact overall insulating glass (IG) production severely. When a required muntin is missing, scratched, dirty or in the wrong order, the IG production line may come to a screeching halt.

One common response to these interruptions is the unintended appearance of what I lightly refer to as “Roving Muntin Gangs.” Obviously I don’t consider insulating glass production associates to be gang members, but it helps to illustrate the unnecessary movement of groups of production personnel through the IG process.

Stop-Start Production CycleThese groups seem to wander the IG department awaiting the next muntin crisis. The line has stopped because it has consumed its supply of muntin assemblies. The gang heads for the stacking area to help get caught up. Sometimes they will kidnap others along the way. These reluctant helpers may include any member of the IG department or anyone who is just passing through. These recruits may not have any idea of quality requirements or assembly procedures but there is always good conversation around the muntin assembly rack. The spray paint flies in an effort to cover up mysterious scratches and the smell of isopropyl alcohol or acetone wafts through the department. It seems to work as the overhead conveyors are soon filled and production resumes.

But wait, there are no muntins for the next batch. The gang moves out and soon they are busy assembling the piles of components that were cut and notched three days ago. They pick up the components, insert the cross and end clips, then stack or hang the completed assemblies. The completed assemblies are rushed to the IG area where the line is stopped again. The line is out of low-E glass: this order will have to wait until tomorrow. The gang returns to the notching stations where components for the next batch are cut to length, notched and abused quickly. They are thrown down, picked up, thrown down, bundled, rubber banded, labeled and sorted in various bins and pigeon holes. Meanwhile the overhead is empty and production has stopped. The gang moves to the assembly area and again the overhead conveyor is filled.

Handle with CareThis may sound like a bit of an exaggeration but at some facilities it has become the accepted routine. Every time a muntin component
is handled, the opportunity for scratching and damage increases. Have you considered completing the entire muntin assembly as the components are cut and notched? Have you looked at ways to deliver the finished assemblies to the assembly area with minimal contact, in the order required?

Do you use spray paint in an attempt to cover scratches? The spray paint may discolor, yellow or peel. It may out-gas and cause fogging. It may contaminate the sealant and cause premature unit failure. Remove the spray
paint from your IG department. Determine the source of the scratching and institute the necessary corrective actions.

How many muntin assemblies have you remade because the original couldn’t be found or was damaged as part of the work in process? Minimize the work in process, and attempt to build and deliver the components and assemblies as they are needed. This will lower scrap, reduce scratching and increase floor space.

Take action to level load your muntin requirements. Attempt to maintain an even and consistent production pace. Keep the associates at the various muntin production cells supplied with the needed raw materials. Make sure they follow required assembly procedures, perform equipment autonomous maintenance and understand the quality standards. Break up the gang.